Internal-combustion engine.



T. REUTER.

INTERNAL COMBUSTION ENGINE. APPLICATION FILED MAY 19, 1910.

1,070,985. Patented Aug. 19,1913.-

llllll/lllll/lll/ y y \A/ITIJESSES m WQ UNITED STATES PATENT OFFICE.

THEODOR REUTER, OF WINTERTHUR, SWITZERLAND, ASSIGNOR TO BUSCH-SIILZER BROS.-DIESEL ENGINE COMPANY, OF ST. LOUIS, MISSOURI, A CORPORATION OF MISSOURI.

INTERNAL-COMBUSTION ENGINE.

To all whom it may concern:

Be it known that I, THEODOR REUTER, engineer, a citizen of the Swiss Republic, residing at 24 Obere Wielandstrasse, Yinterthur, Switzerland, have invented certain new and useful Improvements in Internal- Combustion Engines: and I do hereby declare the following to be a full, clear, and.

A was admitted, the exhaust gases being first expelled by a charge of scavenging air. In this way the weight of the explosive charge was correspondingly increased and the engine accordingly rendered more eflicient. Further, in two-stroke cycle engines of the type wherein air only is first compressed and the explosive charge subsequently ad mitted at the beginning of the ignition stroke, the back pressure in the exhaust pipe has been artificially increased for the purpose of raising the weight of the air.

According to this invention the amount of power developed by a two-stroke cycle engine is increased by forcing into the cylinder at the beginning of the compression stroke, as soon as the exhaust ports are closed, an additional chargeof air, this charge being mixed or brought into contact with therequisite quantity of fuel only on or after completion of the compression stroke.

The accompanying drawings show diagrammatically in vertical section three constructions of engine according to this invention, Figure 1 being a vertical section through an engine cylinder and certain of its valve ports, Fig. 2 a similar view of modified type and Fig. 3 a similar view of a further modification.

In the construction shown by way of example in Fig. 1, the cylinder a in which a piston 11 reciprocates has exhaust ports or slots 0 formed in its wall, scavenging air being suppliedthrough the pipe f and ad- Specification of Letters Patent.

Application filed May 19, 1910.

Patented Aug. 19,1913.

Serial No. 562,276.

mission valve (I. At the endlof the expansion or working stroke the piston 72 opens the exhaust ports 0, and the exhaust gases, which are at more than atmospheric pressure, escape. The scavenging air valve 0'- is then opened and the charge of air so admitted drives out the remaining waste gases, thus charging the cylinder with fresh air. In the meantime the crank has passed through its dead center so that the piston rises and closes the exhaust ports. At that moment the pressure in the cylinder is only slightly in excess of that in the exhaust pipe, but in any case considerably lower than the pressure in the air pipe. By keeping the valve (Z open for a long time the pressure in the cylinder is caused to rise until it finally equals that of the air in the supply pipe 7. It will therefore be seen that this invention difi'ers from others having the same object, in that only the air inlet, and not that through which the explosive mixture is admitted, is opened for a longer period. The action in the present invention is also different, namely it is much more. thorough than in engines where the entire charge is compressed by the piston. If it is remembered that the action of the combustion taking place when the piston is in its highest position is dependent on the .quantity of fuel burnt, which in its turn depends on the quantity of oxygen or air, itwill be obvious that in order to obtain the most powerful combustion it is necessary to have the greatest possible weight of'air.

In internal combustion engines where the entire charge is compressed by the piston, an increase in the pressure at which the charge is introduced can only be the effect of joint increase of air and fuel, the increaseof the former being proportional to the increase of the latter and hence relatively slight, while in engines according to this invention, where the fuel is introduced only after compression of the air, the increase in pressure corresponds solely to the increase in the weight of the air.

Fig. 2 shows a construction in which the admission of the scavenging air is effected by means of two valves and the exhaust takes place in this case through a single valve. The operation of this construction of engine is as follows :When the piston is about 15% from its lowest point the exhaust valve is opened, the pressure in the cylinder falls, and the valve d opens to admit reached that of the scavenging air, the valve- 72- is also closed. The subsequent admission of scavenging air does not, therefore, take place in this case through all the inlet ports but only through one of them. If desired several valves could be provided in place of the two valves h and d, the subsequent admission of additional air in that case taking place only through some of these valves.

It has been assumed here that the pressure of the scavenging air in the supply pipes of the two or all the air valves is the same, but by employing two or more valves it is possible to use scavenging air at diiferentupressures. For the economical working of the engine it is advantageous to admit through one valve or set of valves-for instance, the valve (Zair ata low pressure, the valve or valves h admitting air at a slightly higher pressure. In this way it is possible to increase the weight of air without making the quantity of the scavenging air very great, as would be the case if air at higher pressure were also admitted through the valve d. The power consumed in obtaining scavenging air is therefore reduced with a resultant increase in eficiency;

Fig. 3 shows a construct-ion in which the scavenging air is supplied to the engine cylinder through ports controlled by the pisten, the exhaust takingiplace in the same manner. The supply pipe leading to the upper slots 9 is controlled by a valve h to prevent premature communication with the cylinder. During its down-stroke the piston first uncovers air admission ports 9, but the valve it remains closed. The exhaust ports 0 are thereupon opened and finally when the pressure in the engine cylinder has sunk to about that of the scavenging pres sure, the air admission ports dare also uncovered. At that moment the valve h is opened and the scavenging air passes into the engine cylinder both through the ports 9 and d. During the return stroke the piston closes consecutively theports d, c, and finally 9. Somewhat later the valve 7:, is also closed again. A subsequent additional charge of scavenging air thus is admitted through the ports g after the exhaust ports are closed. By means-of the valve h air can be admitted through the ports 9 later than the time mentioned. The pressure of the omcat scavenging air can be made equal for both air supply pipes f and i, but as explained with reference to the construction shown in Fig. 2, also the pipes 2' and f can be used. to

stroke, the other charge being continued for a longer time, and mixing fuel-with the body of air in the cylinder only on or after the completion of thecompression stroke, substantially as described.

2. The method of operating a two-cycle internal combustion engine, which consists in admitting separate charges of air, at different pressures respectively, into the cylinder after the completion of the working stroke and-when the exhaust port is opened, then, on the compression stroke, closing the exhaust port and cutting ofi the low pressure air, finally cutting ofi the high pressure air, and then mixing fuel with the body of air in the cylinder only on or after the completion of the compression stroke, substantially as described.

3. In a two-cycle internal combustion engine, a cylinder having an exhaust port, a piston in said cvlinder, means to introduce a charge of'scavenging air into the cylinder at the completion of the working stroke and during the time the exhaust port is open, and other means to admit a noncombustible charge of air to the cylinder during the initial part of the compression stroke, substantiallyas described.

4. In a two-cycle internal combustion engine, a cylinder having an exhaust port, a piston in said cylinder, means to admit a charge of scavenging air to the cylinder, and other means to admit air tov the cylinder,

during the initial part of the compression stroke, comprising a piston controlled port in the cylinder wall, substantially as described.

5. In a two-cycle internal combustion engine, a cylinder, a piston therein; means to admit scavenging air to the cylinder, and means to supply additional air to the cylinder during the initial part of the compression stroke, comprising a piston controlled port in the cylinder wall, and a valve to control communication with said port, substantially as described. i

6. In a two-cycle internal combustion engine, a cylinder, a piston therein, a piston controlled exhaust port, a piston controlled inlet port for scavenging air, and a second piston cont-rolled air inlet port which is closed by the piston later than the-exhaust port, during the initial part of the compression stroke, substantially as described.

7 The method of operating internal combustion engines which comprises the following: (1) establishing a body of air in the engine cylinder immediately following the exhaust of the preceding combustion, (2) compressing such air by the inward stroke of the piston, (3) during such compression add--- ing more air to such body of air to increase the Weight of the charge ofair; (4) thereafter injecting a charge of fuel into such air corresponding to the pressure and weight thereof at or about the compression dead center, and permitting the ignited-fuel and air to\ expand against the piston and prpduce the ensuing working stroke.

8'. In an lnternal combustion engine, a'.

cylinder, an exhaust port therefor, an inlet port, for scavenging air, anda piston controlled lnlet port for additional air, which remains open after the exhaust port is' closed, substantially as described In testimony whereof I have afiixed my 2.5 

